This invention relates in general to a computer-input device and in particular to a cursor-pointing device (cursor control stick), of a notebook-type portable computer, cellular phone, personal digital assistant, or similar device.
A finger mouse or cursor control stick, as used in this application, is a man-machine interface device, which controls the motion of a computer display cursor. In particular, a control stick is a type of miniature joystick, which is intended to be operated by the tip of one finger of the user.
Typically, a control stick is mounted in a central location on a computer keyboard, such as between the “G”, “H” and “B” keys on a standard “QWERTY”-type keyboard. The control stick has a position sensing mechanism, which detects horizontal pressure in any horizontal direction. The cursor moves in a direction that corresponds to the direction of pressure exerted on the control stick and, in some embodiments, at a speed that corresponds to the amount of pressure exerted on the control stick. The control stick includes an elongated shaft. The shaft of the control stick has a small diameter, thus allowing the control stick to be mounted between the keys of the computer keyboard without causing the placement of the keys to vary greatly from that expected by an experienced user. A cap is typically removably mounted on the upper end of the control stick shaft, in order to provide an enlarged contact surface for a user to press against on the small diameter shaft of the control stick.
Heins, U.S. Pat. No. 6,019,534, discloses a gripping device for a writing instrument with a plurality of annular ribs formed of soft rubber with an internal gel filled chamber. It is known to use a gel material confined in a chamber as is shown in Heins.